This Indian Standard outlines the code of practice for designing and constructing elevated reinforced concrete water tanks. It specifies the materials, loads (including hydrostatic, wind, and seismic), design principles based on the working stress method to ensure water tightness, and construction and testing procedures.
Covers recommendations for the design and construction of elevated reinforced concrete water tanks.
Quick Reference Values
Design methodWorking Stress Method (WSM)
Minimum grade of concreteM20
Maximum permissible direct tensile stress in steel (High Yield Strength Deformed bars)125 N/mm²
Maximum permissible direct tensile stress in steel (Mild Steel bars)115 N/mm²
Minimum reinforcement in walls (up to 100mm thick)0.3% of the gross cross-sectional area
Minimum freeboard150 mm
Key Formulas
Hoop Tension (T) = w * H * D / 2 — For circular tank walls, where w is density of liquid, H is depth, D is diameter
Practical Notes
This code is based on the Working Stress Method (WSM), not the modern Limit State Method (LSM). Permissible stresses are intentionally kept low to control cracking.
While not officially superseded, current practice often involves using the more comprehensive IS 3370 (Parts 1-4) for general liquid retaining structures in conjunction with IS 1893 (Part 2) for seismic design of liquid retaining tanks.
The primary design consideration for reinforcement is crack width control, not just yielding strength, hence the low allowable tensile stresses in steel.